Motor-vehicle.



No. 742,413. PATENTED 001". 27, 1903.

' J. W. GRUBBSL MOTOR VEHICLE.

APPLICATION FILED FEB. 10. 1903.

no MODEL.

W/TNESS :7. [/VVE/VTGR Patented October 27, 1903.

PATENT O FICE.

JOHN WORTMAN GRUBBS, OF LATROBE, PENNSYLVANIA.

MOTOR-VEHICLE.

SPECIFICATION forming part of Letters Patent N 0. 742,413, dated October 27, 1903.

Application filed February 19, 1903. $erial No. 142,780. (No model.) v

To aZZ whom it may concern:

Be it known that 1, JOHN WORTMAN GRUBBS, acitizen of the United States, residing at Latrobe, in the county of Westmoreland and State of Pennsylvania, have invented certain new and useful Improvements in Motor-Vehicles; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon',which form a part of this specification.

My invention relates to motor-vehicles, but more particularly to motor-cycles,but specifically to the gearing-and-belt arrangement thereof; and my invention has for its object to provide a device for reducing the friction caused by the very taut belt as at present used on motor-cycles and the like.

A further object of my invention is to provide a device which will allow the drivingbelt on a motor-cycle or the like to be comparatively slack, which will at the same time cause said belt to be comparatively free from any slipping on the driving-pulley.

A further object of my invention is to provide a novel'belt-tightener.

A further object of my invention is to provide a belt-tightener which helps to drive the belt.

With all these objects in view my invention consists in the novel arrangement and construction of my combined belt tightener and driver.

My invention also consists in certain other novel features of construction and in combination of parts, which will be first described, and afterward specifically pointed outin the appended claims.

Referring to the accompanying drawings, Figure 1 is an elevation of a portion of a motor-cycle provided with my invention. Fig. 2 is an elevation of the driving-pulley and mycombinedbelt tighteneranddriver. Fig.

3 is a horizontal section taken through the center of Fig. 2.

Like numerals of reference indicate the same parts throughout the several figures.

It might be well to state that the greatest difficultyv encountered with driving-belts on motor-cycles is caused by the fact thatin order to get sufficient power from the motor the driving-pulley must necessarily be constructed of a much smaller diameter than the wheelpulley. Consequently that portion of the periphery of the driving-pulley which is engaged by the driving-belt is so small in comparison with the surface engaged by the driving-belt on the wheel-pulley that there is the greatest tendency on the part of the belt to slip on the driving-pulley. In order to overcome this, the belt must be kept very tight,

which causes undue friction, and the continual stretching of the belt, due to the strain on the same, makes the arrangement far from satisfactory. It is for the purpose of overcoming every one of these defects in a simple manner that I have constructed my present invention, which I will now fully describe. I

Referring to the accompanying drawings by reference-numerals, 1 indicates that portion of a bicycle which is sufficient to illustrate my invention, and 2 is the -motor..

3 indicates mydriving-pulley, which is provided around itsperiphery with a toothed flange t, and 5 indicates my combined belttightening and auxiliarydrivingpulley,which may be of the samediameter as the drivingpulley proper or as much larger as circumstances will permit, as the larger this idlerpulley the more driving-surface will be in contact with the belt; but any increase in size must be accompanied by a proportionate increase of its toothed flange 6.

7 indicates a lever,'which is fulcrumed on an annular shoulder 7', formed on the motor-casing 10 around the shaft 8 of the driving-pulley which carries the pulley 5, and said lever is provided with a handle 9 for manipulating the same.

10 indicates the casing of the motor, and along the rear of the periphery thereof I provide a series of ratchet-teeth 11. (Shown in dotted lines in Fig. 2.) On the said lever '7 I provide a bracket 12, and on the end of said bracket is a guide '13, which straddles the said ratchet-teeth 11 and holds the entire arrangement in position and prevents any lateral movement thereof. 14 indicates a pawl, which is pivoted to said bracket at l5-and which engages the ratchet-teeth 11, as shown in dotted lines in Fig. 2.

16 indicates the casing covering toothed portion of drive-pulleys, protecting belt from same, and 17 is the belt.

It will be seen by referring to Fig. 3 that the pulley 5 is eccentrically journaled on the lever 7, as the axle 18 which carries the bearing-con es 19 passes through an eccentric opening in the pin 20. Consequently by turning said pin the mesh of the gear-teeth on the two pulleys can be nicely adjusted to take up the wear, &c.

Having thus described the several parts of my invention, its operation is as follows: The belt 17 is put on as shown and in the usual manner, and it should be slack enough to allow the lever 7 to be raised so as to bring the pulley 5 into or near the position shown in Fig. 2. Following the course of the belt in Fig. 2 it is plainly seen that it engages quite a portion of the periphery of the pulley 5 and that it is in contact with considerably more than half of the periphery of pulley 3. When the driving-shaft 8 revolves the driving-pulley 3, the pulley 5 is also revolved in the contrary direction, and as the belt passes from the driving-pulley 3 and over the pulley 5 said pulley5 assists in driving the belt. Thus it is evident the driving power exerted on the driving-belt is almost doubled, the effect of which is that a much greater driving power can be given a belt which is comparatively loose than can be given a belt under the present existing arrangements.

I wish it to be understood that the result would be practically the same if two motors were employedone to drive the driving-pulley and the other to drive the pulley 5. In

this event said pulleys could, of course, be

arranged so as not to mesh or be otherwise connected together.

The simplicity of my invention is apparent, and I deem it unnecessary to go further into details of description. I do not, however, wish to be understood as limiting myself to the exact construction herein set forth, as various slight changes may be made in the construction and arrangement of parts which would fallwithin the limit and scope of my invention, and I consider myself clearly entitled to all such changes and modifications.

What I claim as myinvention, and desire to secure by Letters Patent of the United States, 1s-

l. The combination with the driving-pulley of a belt passing over the same, and a belt-tightener in direct engagement with the said driving-pulley.

2. The combination with a driving-pulley and a belt-tightener in direct engagement therewith, of a belt passing over said drivingpulley and said belt-tightener.

3. The combinatian with the driving-pulley of a combined belt tightener and driver in direct engagement therewith, a belt passing over said driving-pulley and over said belt tightener and driver.

4. The combination with a belt anddriving-pnlley of a belttightener eccentrically journaled and in direct engagement with the driving-pulley.

5. The combination with a belt and driving-pulley, of a belt-tightener in direct engagement with said driving-pulley,and means for adjusting said belt-tightener in relation to the driving-pulley.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN VVORTMAN GRUB BS.

Witnesses:

J os. E. BARNETT, JAs. T. HUGHES. 

